Possible meniscus injury

My daughter is a competitive dancer. This summer, her right knee started giving out when she was especially tired and had been dancing a while but without any pain. The frequency increased over the past few months - only while she’s at dance. Thanksgiving week, it happened but this time there was pain and a popping sound when she walks. I’m friends with a sports med ortho who got us in fast, did imaging the same week and was positive it would be a meniscus tear… but MRI didn’t show that. So now we are stuck with PT and not knowing what’s next. He said he may scope it and see what he sees because he still thinks a tear is possible. She’s only 14. Is this possible that a tear didn’t appear? What kind of things do you wish you’d done differently? He said if she has to have surgery it’ll take her out of performing for a year and her whole world revolves around it. I’m just not sure what the right choice is for her, if it’s a tear, given all the negative things I’ve read about the surgery. Any insight?